A new survey says working in an office may be hard on the waistlines of nearly half of U.S. workers.

The survey of more than 5,600 workers, conducted by Harris Interactive for CareerBuilder.com, found that 28 percent of workers have gained more than 10 pounds and 13 percent have gained more than 20 pounds in their current jobs.

Snacking at their desks and eating too much fast food may be part of the problem. The survey found that 58 percent of the workers eat out at work for lunch at least once a week, with more than 12 percent eating out five times a week for lunch.

Some workers said they don't even make it outside the building for lunch, opting to grab something quick from a vending machine. Thirty-eight percent said they eat more junk food at the office than at home and 13 percent said they don't usually eat fruit or vegetables during the work week.

Copyright 2007 by United Press International